Patent application title: ENCLOSURE FOR SURGICAL PROCEDURES

Abstract:

The invention relates to a medical device for performing substantially
bloodless surgery wherein the device comprises a double-skinned chamber
with at least one through-bore.

Claims:

1. A medical device for performing substantially bloodless surgery
comprising an inflatable chamber having a through-bore adapted to receive
a body part of an individual to be operated upon, which chamber in use,
is in fluid communication with a pressurised gas supply for inflating
same and maintaining pressure in said chamber at a selected level
wherein, upon inflation of said chamber the inner and outer walls thereof
are forced thereapart and the inner wall sealingly engages with the site
to be operated upon and the outer wall defines at least a part of a
pressurised chamber in which surgery can take place; and further wherein
said chamber includes at least one portal that allows access to the
inside of the chamber, without significantly affecting the maintenance of
said pressure, whereby said surgery can take place.

2. A medical device according to claim 1 wherein the inner wall of said
chamber is made from a material that can be cut with a scalpel.

3. A medical device according to claim 1 wherein the outer wall is made of
a material that, upon reaching a certain size, will resist further
deformation.

4. A medical device according to claim 1 wherein the inner wall is made
from a different material to the outer wall.

5. A medical device according to claim 1 wherein said device is provided
with a pressure monitoring means in order to monitor the maintenance of
said pressure at said selected level.

6. A medical device according to claim 1 wherein said device is provided
with venting means for venting said pressurised gas from said chamber.

7. A medical device according to claim 1 wherein said device is provided
with a closed circuit gas system whereby pressurised gas delivered to
said chamber is returned to said pressurised gas supply before being
reused to maintain the pressure inside said chamber.

8. A medical device according to claim 1 wherein said device is adapted to
be disposable.

9. A medical device according to claim 1 wherein at least the inside of
said chamber, that is the part that makes contact with the patient, is
provided in a sterilised form.

10. A medical device according to claim 1 wherein said device is provided
with a rigid or semi-rigid framework for positioning the inflatable
device in a spaced relationship from the site to be operated upon,
regardless of the pressure within the chamber.

11. A medical device according to claim 1 wherein said device is provided
with a pair of portals.

12. A medical device according to claim 1 wherein said portals are in the
form of a glove/sleeve arrangement which sealingly engages with a part of
the chamber from which it/they originate.

13. A medical device according to claim 1 wherein said device comprises a
plurality of portals for enabling a plurality of instruments to be used
in, or in association with, the inside of said chamber.

14. A medical device according to claim 1 wherein said chamber is, at
least in part, transparent so that a surgeon can see into the chamber in
order to perform surgery.

15. A medical device according to claim 1 wherein the entire device is
transparent.

16. A medical device according to claim 1 wherein the device is provided
in a prepacked form.

17. A medical device for performing substantially bloodless surgery
comprising an inflatable double-skinned chamber which, in use, is in
fluid communication, via a single inlet means, with a pressurised gas
supply for inflating same and maintaining pressure in said chamber at a
selected level; said chamber being adapted to be placed sealingly against
or about an individual to be treated and including at least one portal
that allows access to the inside of said chamber, without significantly
affecting the maintenance of said pressure, whereby said individual can
be treated characterised in that;said chamber comprises an inner and an
outer skin, the inner skin being made of a relatively thin material that
can be cut with a scalpel and the outer skin being made of a material
that resists deformation on inflation whereby on inflation of said
chamber said inner and outer skins are forced thereapart whereby said
inner skin sealingly engages with the site to be operated upon and the
outer skin defines a pressurised cavity in which surgery takes place.

Description:

[0002]Surgeons endeavour to minimise operative blood loss by making any
incision neat and precise. However, under normal circumstances blood loss
is unavoidable and the amount of blood loss governs the degree of
occlusion that takes place and thus the amount of inadvertent injury to
any structure, vital or otherwise, obscured in a pool of blood. Despite
these best endeavours, it is known for injury to the recurrent laryngeal
nerve to occur during thyroidectomy, for injury to the bile duct during
cholycystectomy and injury to the ureter during pelvic surgery. Various
techniques are employed to reduce blood loss such as, as mentioned,
scrupulous dissection which typically involves controlling the blood
vessels before cutting, but other techniques are also used such as
electro-cautery, argon beam coagulation, ultrasonic dissection, the use
of lasers and haemostatic agents such as cellulose, gelatin and collagen.
However, these techniques only minimise blood loss and are sometimes not
effective as in the case of large vascular tumours, haemangioma and
arteriovenous malformations.

[0003]The unavoidable loss of a significant amount of blood volume
necessitates replacement with blood from a compatible tissue type. But
even where replacement is possible, massive transfusion can be associated
with complications like coagulation derangement, hyperkalaemia and
hypothermia. Moreover, compatible transfusion also carries the risk of
transmission of microbial infections such as HIV, Hepatitis and Malaria.

[0004]It follows from the above that if the surgeon was able to perform
bloodless, or substantially bloodless, surgery then one could avoid the
operative field being occluded by pools of blood and so aid the surgeon
by reducing the possibility of inadvertent injury. Additionally, one
would also reduce the operative time and further, one could avoid the
loss of significant amounts of blood and therefore the need for
transfusion.

[0005]Bloodless surgery is therefore a highly desirable goal and brings
with it any one or more of the following advantages.

[0006]It greatly reduces the need for the collection and storage of blood;
it would overcome some of the difficulties associated with finding an
adequate supply of blood that was classified as being from a rare blood
group; it would make surgery a more feasible option for those with
religious beliefs that prevent them from having blood transfusions; it
would reduce the trauma and complications associated with blood loss and
blood transfusion; it would safeguard against the contamination of staff
with infections contracted by contact with contaminated blood; it would
provide a clean environment in which to perform surgery; it would make
surgery possible at the site of injury in impoverished countries where
facilities are poor, and it would redistribute blood away from the
operative site and thereby help maintain central blood pressure.

[0007]Despite these highly desirable advantages, hitherto, surgery has
always been performed in such a way that an inevitable by product is the
loss of blood and the associated complications.

[0008]Regardless of this status quo we have developed a medical device
that enables surgery to be performed in a bloodless, or substantially
bloodless, environment. By this we mean that we are able to perform
surgery without the loss of blood or without a significant amount of
bleeding such that the operative field remains largely unobscured and the
surgeon is therefore able to see tissue to be treated or operated upon.

[0009]Our medical device is suitable for use both in the operating theatre
and in the field. In the former instance our medical device can be
adapted for use by either a surgeon or a robot. This is also true in the
field but, typically, in the extreme conditions where field surgery has
to be performed it will normally be performed by a surgeon. For example,
where an individual has suffered an accident in a remote location and
surgery needs to be performed immediately, then our medical device will
enable a field surgeon to perform an operation in a bloodless or
substantially bloodless environment.

[0010]Additionally, our medical device is used in stabilising a wound
prior to treatment. For example, where an individual that has suffered an
accident such as a car accident, or the like, and sustained a wound then
the medical device can be placed about the wound in order to prevent any
further blood loss and also promote healing.

[0011]We have found that our medical device actually promotes healing due
to high pressure oxygen and therefore it is used to advantage during
surgery. For example, it may be used during abdominal operations
especially those associated with significant bleeding viz. resection of
tumour of liver, adrenal, renal or retroperitoneum.

STATEMENTS OF INVENTION

[0012]According to a first aspect of the invention there is provided a
medical device for performing substantially bloodless surgery comprising
an inflatable chamber having a through-bore adapted to receive a body
part of an individual to be operated upon, which chamber, in use, is in
fluid communication with a pressurised gas supply for inflating same and
maintaining pressure in said chamber at a selected level wherein, upon
inflation of said chamber the inner and outer walls thereof are forced
thereapart and the inner wall sealingly engages with the site to be
operated upon and the outer wall defines at least a part of a pressurised
chamber in which surgery can take place; and further wherein said chamber
includes at least one portal that allows access to the inside of the
chamber, without significantly affecting the maintenance of said
pressure, whereby said surgery can take place.

[0013]In a preferred embodiment of the invention the inner wall is made of
a material that can be cut with a scalpel whereas the outer wall
comprises a material that upon reaching a certain size will resist
further deformation.

[0014]According to a second aspect of the invention there is provided a
medical device for performing substantially bloodless surgery comprising
an inflatable double-skinned chamber which, in use, is in fluid
communication, via a single inlet means, with a pressurised gas supply
for inflating same and maintaining pressure in said chamber at a selected
level; said chamber being adapted to be placed sealingly against or about
an individual to be treated and including at least one portal that allows
access to the inside of said chamber, without significantly affecting the
maintenance of said pressure, whereby said individual can be treated
characterised in that;

[0015]said chamber comprises an inner and an outer skin, the inner skin
being made of a relatively thin material that can be cut with a scalpel
and the outer skin being made of a material that resists deformation on
inflation whereby on inflation of said chamber said inner and outer skins
are forced thereapart whereby said inner skin sealingly engages with the
site to be operated upon and the outer skin defines a pressurised cavity
in which surgery takes place.

[0016]Typically, said inner and outer walls or skins comprise two separate
materials. However, it is within the scope of the invention for the inner
and outer walls or skins to be made of the same material providing the
material fulfils all of the stated properties. Thus one can use a single
material that is suitably thin to be cut with a scalpel but also
resistant to deformation on inflation. However, more usually, two
separate materials will be used and the inner material is most usually a
plastics material of a transparent and thin nature. As an alternative a
thin latex material could be used but it would, preferably, have to be of
a sort that does not elicit an allergic reaction. The outer wall or skin
is most usually a plastics material although, because this material does
not have direct contact with a patient's skin it can be a latex material
providing, in either case, that it resists extension at the pressures
that are used in order to perform the surgery. These pressures are
typically no greater than systolic pressure, including systolic pressure
of an individual experiencing high blood pressure but, most typically,
especially where superficial surgery takes place to remove moles,
epithelial growths, correct varicose veins or remove other surface
lesions such as cancers and the like, then pressures significantly below
systolic may be used because the surgeon is unlikely to be cutting an
artery or a vein, rather the surgeon will be cutting through smaller
blood vessels such as capillaries.

[0017]In use the medical device is placed sealingly against or about a
part of an individual using the inner wall or skin as a seal. Whilst it
is desirable that the seal is as tight as possible, it need not be
hermetic provided the pressure within the chamber can be maintained at a
selected level. In other words, some leakage of gas can be tolerated
provided it can be replaced by the pressurised gas supply in order to
maintain the elevated pressure within the chamber. Further, techniques
are known for maintaining a seal about or against the body of an
individual and they may include the use of creams, emulsions, suspensions
or the like which when placed on the body of an individual help to form a
tighter seal with a sealing member.

[0018]In use, once the medical device has been inflated the surgeon uses
said portal in order to gain access to the pressurised chamber and, using
a scalpel, cuts through both the inner wall or skin and the patient's
tissue in order to gain access to the organ or tissue to be treated. It
is therefore desirable for the inner wall or skin to be made of a thin
material that can be cut with a scalpel but also a material with
relatively clinging properties so that upon exposure to a pressurised gas
the material is pushed sealingly against the skin of a patient and, in
effect, acts as a second skin. This means that once incision has taken
place the patient's tissues are exposed to the pressure inside the
medical device.

[0019]It will therefore be apparent to one skilled in the art that the
medical device of the invention acts to reverse the pressure gradient
across vascular tissue and so prevent the loss of blood from the vascular
system by maintaining an elevated pressure, which is greater than the
tissue blood pressure at the site of the operation or, ideally, an
elevated pressure to a maximum that approximates to, or about, systolic
blood pressure; so ensuring that leakage of blood is avoided and
therefore the area within the chamber can be treated without the
operative field being obscured.

[0020]In a preferred embodiment of the invention said medical device is a
transparent chamber.

[0021]Reference herein to a transparent chamber includes reference to a
chamber that is transparent to the extent that a surgeon can see into the
chamber sufficiently to perform surgery. It is therefore not necessary
for the entire chamber to be transparent and, indeed, conventionally,
modern surgery is typically undertaken by restricting the operative field
to an area of tissue that is delineated by the use of surgical drapes. It
is therefore sufficient for the chamber to be transparent to the extent
that the surgeon is simply able to perform the operation. Although, in
some embodiments of the invention the entire chamber is transparent; this
is particularly preferred where more than one individual has access to
the inside of said chamber.

[0022]In an alternative aspect of the invention the chamber may be opaque
or lacking any transparency. This particular version of the invention is
suited for use in relation to robotic surgery and, ideally, associated
camera means are provided whereby a surgeon can operate the robot without
needing to see through the walls of the medical device.

[0023]In a preferred embodiment of the invention said medical device is
provided with a pressure monitoring means in order to monitor the
maintenance of said pressure at said selected level and, ideally, venting
means for venting pressurised gas within said chamber. As will be
apparent to those skilled in the art the selective control of the supply
of pressured gas and the venting thereof enables the maintenance of
pressure inside said chamber at said selected level. Moreover, in an
alternative embodiment of the invention a closed circuit gas system may
be provided which reduces the amount of gas required to run the system.

[0024]Advantageously, we have discovered that whilst our medical device,
through manipulation of the external pressure at the site of the wound,
prevents blood loss it does not prevent blood flow through intact
vessels. Therefore, unlike a tourniquet, a surgeon can perform an
operation confident in the knowledge that tissue distal and proximal to
the site of the surgery is receiving an adequate supply of blood. This
means that there are no time limits on the length of the operation and
that tissue surrounding or remote from the site of the operation will not
be damaged.

[0025]In a further preferred embodiment of the invention said medical
device is adapted to be disposable and is therefore, advantageously,
prepared with, at least, the surface that makes contact with the patient
sterilised. As will be apparent to those skilled in the art the
inflatable aspect of the invention lends itself most suitably to being
disposable. Indeed, the inflatable aspect of the invention lends itself
to being provided in a foldable, and so pre-packed, form so that, when
used, the disposable chamber can be removed from sterilised packaging and
placed over the operative site or wound prior to surgery or treatment.

[0026]Advantageously, the inflatable medical device is ideally provided
with a rigid or semi-rigid framework for positioning the inflatable
material in spaced relationship with respect to the operative site,
regardless of the pressure within the chamber.

[0027]In a preferred embodiment of the invention said chamber is provided
with a pair of portals, one for each hand/arm of the surgeon.
Advantageously, these portals are in the form of a glove/sleeve
arrangement, which the surgeon can insert his hands into, and which
sealingly engage with a part of the chamber from which they originate.

[0028]In any preferred embodiment of the invention a plurality of portals
may be provided for enabling a plurality of instruments to be used in, or
in association with, the inside of said chamber. For example, further
portals may be provided to allow access for a catheter, laparoscopic
device or the like.

[0029]During surgery the pressure inside said chamber is maintained at a
level equal to or, more typically, greater than the tissue blood pressure
at the site of operation or systolic pressure. Thus, typically, when the
medical device is used the systolic pressure of the patient governs the
level of pressure maintained within the chamber. Typically, throughout
the operation the patient's systolic pressure is monitored in
conventional fashion and appropriate adjustments are made to the pressure
within the chamber. The systolic blood pressure of the patient will be
continuously monitored by an intra-arterial cannula. This pressure
reading will be fed to a computer which will regulate the gas compressor
pump such that the chamber pressure is maintained, typically, but not
exclusively, to just above systolic blood pressure.

[0030]Advantageously, the device of the invention provides an effective
seal for use during surgery because the entire, or almost the entire,
inner wall or skin of the chamber sealingly engages with the entire part
of the body that is inserted into the chamber thus increasing the
effective surface area of the seal. The device of the invention therefore
not only provides sufficient pressure for a surgeon to be able to perform
substantially bloodless surgery but it also provides sufficient pressure
for the device to sealingly engage with a part of the body that has been
inserted into the chamber.

[0031]In yet a further preferred embodiment of the invention the
pressurised gas supply is oxygen or a mixture of oxygen and at least one
other selected gas.

[0032]In yet a further preferred embodiment of the invention the medical
device is for use on either humans or animals.

[0033]An embodiment of the invention will now be illustrated by way of
example only with reference to FIGS. 1 to 4 wherein:

[0034]FIG. 1 shows an illustrative view of the medical device in
accordance with the invention when used in a surgical environment;

[0035]FIG. 2 shows a side end view of a medical device in accordance with
the invention;

[0036]FIG. 3 shows various views of the medical device in accordance with
the invention: FIG. 3A shows a side end view, FIG. 3B shows a lateral
side view, FIG. 3c shows a perspective view, and FIG. 3D shows a plan
view;

[0037]FIG. 4 shows a perspective view of a further medical device in
accordance with the invention when used to perform limb surgery; and

[0038]FIG. 5 shows a second embodiment of a second sleeve member according
to the invention.

[0039]Referring to the figures and firstly to FIG. 1, there is shown a
medical device when used in an operating theatre. The device 1 has been
placed sealingly against the abdomen of the patient to be treated. Device
1 is in fluid communication with a pressurised gas supply 2 which is used
to inflate device 1 and, subsequently, maintain the pressure inside
device 1 at a substantially constant level. The remainder of the
operating theatre is a standard and the patient is ventilated in the
usual fashion using conventional equipment.

[0040]In FIG. 2 the medical device of the invention is shown in isolation
but in an inflated condition. Thus, although not shown, the medical
device 1 is in fluid communication with a pressurised gas supply.

[0041]Medical device 1 comprises a double skin arrangement including an
outer skin 3 and an inner skin 4. The properties of these two skins vary
as each is adapted for a specific purpose. Skin 3 and skin 4 may be made
from the same material providing the material has the requisite
properties. Alternatively, skin 3 may be made from a different material
to that of skin 4 and, in any event, skin 3 is made from a material that
has properties suitable for its intended purpose and skin 4 is made from
a material that has properties suitable for its intended purpose. The
device shown in FIG. 2 is typically for use during abdominal surgery and
therefore comprises a suitably sized hollow core 5 through which the body
of an individual is inserted. Once the medical device is inflated
pressurised gas enters same and so exerts a pressure, indicated by the
arrows, on the inner skin 4 and the outer skin 3. In this embodiment
inner skin 4 is made from a different material to that of outer skin 3.
Inner skin 4 is made of a thin and, typically, elastic material which,
under pressure, clings to the skin of the patient to be treated. In
contrast, outer skin 3 is made of a tougher material which, once
inflated, resists any further deformation or stretching and so is able to
help maintain the pressure within the chamber at a relatively constant
level.

[0042]Although not shown in FIG. 2, pressure monitoring means are provided
for monitoring the pressure within the chamber so that if the pressure
should fall, as a result of leakage, more gas can be introduced into the
chamber in order to maintain the pressure at a desired level. Moreover,
venting means are typically associated with the chamber in order to
facilitate the maintenance of this pressure. So, for example, should the
pressure rise above a desired level then the venting means can be used in
order to release some of the pressure within the chamber.

[0043]Also shown in FIG. 2 are portals 6. Typically, a pair of portals are
provided on the left hand side of the chamber and an identical pair of
portals are provided on the right hand side of the chamber so that the
surgeon can choose on which side of the operating table he wishes to
stand. Additionally, although not shown, further portals may be provided
for introducing surgical equipment into the chamber for use during the
surgical procedure. These latter portals comprise sealable entry points
whereby a surgical instrument can be introduced to the inside of the
chamber.

[0044]As those skilled in the art will appreciate, it may be desirable,
immediately prior to introducing a piece of surgical equipment during an
operation to allow the pressure within the chamber to rise slightly so
that opening of a portal to introduce the equipment does not
deleteriously affect the operation.

[0045]Referring to FIG. 3, the embodiment of the invention shown in FIGS.
1 and 2 is illustrated in greater detail with reference to different
views. FIG. 3A is essentially the same view as shown in FIG. 2 except
that the portals are shown on the upper sides of the chamber and
penetrating into the chamber at right angles. FIG. 3B shows a side view
of the chamber where it can be seen that a pair of spaced portals are
provided at a desired height and below same there is provided a pair of
venting means. FIG. 3c shows a perspective view of the chamber. The
hollow core 5, through which an individual is inserted, is clearly seen,
and further it can be seen that, once inflated, the cavity forms a
dome-shaped structure above the body of the patient. FIG. 3D shows a plan
view of the medical device and it can be seen that a pair of portals are
provided on either side of the medical device.

[0046]Referring now to FIG. 4, there is shown a medical device adapted for
use in limb surgery. This medical device essentially comprises a
double-skinned chamber which is fashioned in the form of a sleeve. Once
again, the inner skin 4 is adapted to sealingly engage with the body of
the patient and so forms a tight, flattened seal against, in this
illustration, a patient's arm. In contrast, the outer skin 3, once
inflated, is spaced remote from inner skin 4 and so defines the
pressurised chamber which, via gas supply means 7 and gas venting means
8, is maintained at a relatively constant pressure. Also shown in FIG. 4
are the sealed portals 6 through which a surgeon gains access to the
pressurised chamber. In this illustration of the device a scalpel has
been placed inside the chamber and the surgeon has used same in order to
cut through inner skin 4 and also the tissue of the patient. Thus a
single incision gives the surgeon access to a patient's tissue and,
because of the properties of inner skin 4, the seal is not broken.

[0047]During use, a surgeon uses the pair of sleeved portals 7 in order to
gain access to the inside of the device. The sleeved portals are shown in
greater detail in FIG. 5 and in one embodiment of the invention the
sleeves are provided as releasable attachments to the medical device
which, in use, sealingly engage with the device in order to prevent
pressure loss within the chamber.

[0048]In FIG. 5 the sleeve member comprises an elasticated cuff for
positioning the sleeve about the hand/arm of the surgeon, it also
comprises an annular sealing member 10 which sealingly engages with the
rim defining the aperture of portal 7.

[0049]A range of portals can be built into the device of the invention to
provide access for various devices such as, without limitation, a gas
inlet with valve; a pressure monitoring gauge; arm portals; endoscopic or
laparoscopic instruments; access for intravenous and fluid lines; access
for anaesthetic endotracheal tube; in/out gas blocks; gas venting means;
temperature and humidity monitoring means; and access for catheters.

[0050]Although not shown, in some embodiments, an inflatable structure is
provided with skeletal supports in the form of rigid or semi-rigid hoops
the purpose of which is to maintain the medical device in space
relationship with the patient so ensuring that when the pressure within
the medical device is reduced the device does not completely collapse and
make contact with the patient.

[0051]Referring again to FIGS. 1 and 4, although not shown the device can
be linked to a closed system gas generator which provides pressurised gas
via a closed circuit system. Ideally, the closed circuit system is
provided with a pressure monitoring means and associated valve means.
Selective operation of valves in conjunction with the gas generator
enables the pressure within the bag-like chamber to be maintained at a
selected level. This closed system circuit provides for the efficient use
of pressurised gas within the system.

[0052]Whilst the invention has been particularly described with reference
to a medical device suitable for performing abdominal or limb surgery, it
will be apparent to those skilled in the art that the shape and size of
the medical device may take different forms according to the nature of
the surgery that is to be performed.

[0053]The device is most advantageously used with a pressurised oxygen
supply because oxygen promotes healing and therefore use of the device
with this choice of gas not only enables bloodless surgery to be
undertaken but also, at the same time, promotes healing of the tissue
that has been operated upon.

[0054]In use, once a surgeon has performed surgery, he or she may,
advantageously, lower the pressure within the chamber to a point at which
blood leakage from vessels that have yet to be sealed or ligated is
visible. In this way, the surgeon can see those vessels which require
attention and then by increasing pressure within the chamber block any
loss of blood from these vessels prior to taking steps to seal them. This
procedure can be repeated however many times are necessary in order to
successfully conclude the surgery.

[0055]If desirable, the device can be used to perform robotic surgery and,
in this instance, a video camera will be provided within the pressurised
chamber so that a surgeon, seated at a remote location, can view the
operative field.

[0056]The device will be especially advantageous for the performance of
Robotic Surgery: [0057](a) it will provide a clear operative field
enhancing the visibility of vital organs. This in turn will render the
operation more precise and reduce the damage to vital structures;
[0058](b) it will make the performance of operative procedure faster as
no time will be wasted in controlling the haemorrhage; and [0059](c)
controlling haemorrhage during laparoscopic/endoscopic procedures
manually or with robotic control requires removing the blood with some
absorbent swab or a suction cannula. A dry bloodless field will obviate
the need of an extra instrument to mop or suck the blood.

[0060]Further, we prefer to use oxygen to pressurise the medical device
because, whilst unlikely, there is a theoretical possibility of air
embolism if a large amount of air enters the venous circulation due to
the insoluble nature of nitrogen. However, since we are using pure
oxygen, which is highly soluble in blood, the chances of an embolism
occurring are almost minimal. The patient will be monitored for features
of embolism by transcutaneous oxygen saturation recording and monitoring
of heart for presence of gas bubbles by a transesophageal
echocardiography during the operation. Other potential benefits of using
oxygen inside the pressurised chamber are: [0061](a) salutary effect of
oxygen in promoting wound healing; [0062](b) enhancing collagen synthesis
in the wound reducing the risk of wound disruption; [0063](c) prevention
of wound infection; and [0064](d) improving viability of skin and muscle
flaps in reconstructive surgery.